NEXT

PALEOZOIC ERA

PERMIAN PERIOD

299-252 million years ago

HOME
PREVIOUS
therapsid

The vertebral column and shoulder became more like those of mammals.

In therapsid vertebral column, the intercentra were lost in the trunk but still existed in the neck. In the shoulder, the glenoid cavity and acetabulum became more open ventrally. The scapula evolved an acromion process.